Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6da0d95463fc366085dcf737cdb2fe1f50b54d3a162df8db38ddab3c7de566c' 
  AND token = 'b0tOmjCRzLt9WsO9xgQjFKz9UHGFbzXQT6sNeZ0wTPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}